This disclosure relates to a drive unit using a polymer actuator device, and a lens module and an image pickup unit which are provided with the drive unit.
In recent years, for example, portable electronic units such as a mobile phone, a personal computer (PC), and a PDA (Personal Digital Assistant) have become remarkably multifunctional, and the portable electronic unit with a lens module thereby having an image pickup function has become general. In such portable electronic units, focusing and zooming are performed by moving a lens in the lens module in an optical axis direction.
In general, the lens in the lens module is typically moved by using a voice coil motor or a stepping motor as a drive section. Meanwhile, recently, a unit employing a predetermined actuator device as a drive section has been developed from the viewpoint of miniaturization. Examples of such an actuator device include a polymer actuator device (see, for example, Japanese Unexamined Patent Application Publications No. 2006-293006 and No. 2006-172635). The polymer actuator device is a device in which, for example, an ion-exchange resin film is interposed between a pair of electrodes. In the polymer actuator device, the ion-exchange resin film is displaced in a direction orthogonal to a film surface, due to occurrence of a potential difference between the pair of electrodes.